Brake Duct Routing

So, I have replaced the fog lights on my E30 with brake ducts, and I need to know where run the hoses. Has anybody done this before?

You need to aim them at the center of the rotors of you can, and let the ducting pull the air out through the center of the rotor. As for routing to get there, just keep them clear of the tires at full lock.

Keith wrote: You need to aim them at the center of the rotors of you can, and let the ducting pull the air out through the center of the rotor. As for routing to get there, just keep them clear of the tires at full lock.

Not just full lock, but also full droop and jounce. This is easier said than done on some cars! The backing plates can make for a handy mount for the ducts, on our LeMons car we used some scraps from a muffler shop that matched the diameter of our ducts (ahem, clothes dryer ducts) and cut a hole in the backing plate to match. Weld them up and you've got a near free duct. Use a hose clamp around the duct to backing plate assembly and it holds quite firmly. One nice feature to the dryer duct in addition to being super cheap is that you can squish the wire coil in there to make it oval where necessary for clearance.

Bryce

You can do that to the more expensive ducts too :)

Keith wrote: You can do that to the more expensive ducts too :)

Here's what I've used in the past, more expensive but less fragile than dryer ducting. Plan out your route and use lots of zip ties to anchor your ducting:

http://www.mcmaster.com/#53145K67

what about shop vac hose? Cheap and tuff, get it at any HW store. I think Im gonna do the same with the foglight plates in my infiniti.

Sorry for the thread jack, but is there any downside on installing these in a DD?

They were cheaper than the foglights, which would just break again.

Oh, I already have the hose. It came with the ducts. Apparently, I need backing plates, though.

You might be able to get away without backing plates, I've done it.

There's no real downside on a DD that I can think of. You do want to make sure that your hose can handle whatever heat it's exposed to. Since we're talking about brakes, that could be pretty hot.

also, without the backing plates (aka dust shields or more appropriately heat shields), you run the risk of cooking the grease and / or burning the grease boots on your ball joints.

Keith wrote: You do want to make sure that your hose can handle whatever heat it's exposed to. Since we're talking about brakes, that could be pretty hot.

ooohhh ..dually noted.

AngryCorvair wrote: also, without the backing plates (aka dust shields or more appropriately *heat* shields), you run the risk of cooking the grease and / or burning the grease boots on your ball joints.

Sorry, I didn't make myself clear. I have backing plates, but they don't have hose holes in them. Can a piece of pipe or something be welded on to them?

As long as they are steel you can cut the hole and weld the pipe in place.

I like these fans the best, I don't know how well they worked but they look good. They were made from Corvair cooling fans

This may help you. http://www.eskimo.com/~mikeg/S2000/ducting/ Just do a search on brake ducting and see what comes up.

Tommy Suddard wrote:

AngryCorvair wrote: also, without the backing plates (aka dust shields or more appropriately *heat* shields), you run the risk of cooking the grease and / or burning the grease boots on your ball joints.

Sorry, I didn't make myself clear. I have backing plates, but they don't have hose holes in them. Can a piece of pipe or something be welded on to them?

don't complicate things too much. welding is unnecessary. a quick and dirty solution is to find a local corvair freak and see if they've got a couple of "fresh air hose adapters" which is the part that screws to the engine top shroud, on the front of the top shroud, on the passenger side, probably obscured from view by the turbo on your mom's spyder. it's a neat little sheetmetal piece that's retained by three screws. you could very easily pop-rivet these to your disc brake heat shields, then use a hose clamp to attach your duct hose to them.

adding corvair parts to a bmw is always the right thing to do.

Solution to your backing plate problem. I just ordered a set: Gruvenparts backing plates There's currently a group buy going on for these for Spec E30 racers for $99. I'd bet a little name dropping could get you that price.

Wouldnt there be a problem with routing air in a rainstorm?

you have lovely holes in the LCA to ziptie to...

honestly , probably not problem. not much rain will make it in the opening, and even less will make it past the first bend in the pipe with any velocity...

On an E36, I've taken a set of tin snips and "slotted" the backing plate, bent it back and slid the hose over it. Picture an "H" then fold back from the center. This was a dedicated car though so things like AC condensers and fender liners had been removed.

Like said above - you need to get the air to the center, which on an E30 is a bit of a cramped affair. I haven't tried this - but using thin walled tube affixed to some new welded brackets on the parts that move with the wheel (plate, strut) you could fashion a pretty inlet to connect some flex hose on an "as-needed" basis so you could have a normal turning radius all the days of the year you are not at the track, and then whip out some hose and clamps when you get there.

Keith wrote: You can do that to the more expensive ducts too :)

The real ducts I've worked with had much more substantial wire in them, so they were a lot harder to squish flat. The dryer ducting was very wimpy so it squished flat when you looked at it wrong.

Bryce

It's harder, but you can do it.

The stock ducts on Project Spec E30 seemed more than adequate at keeping the brakes happy on track, I never had fade problems with the front. You don't need to go too crazy until you determine that fade is actually a problem for your application.

Be sure to check the clearances with the steering from lock to lock, it's really easy to crush your nice new brake ducts or rip them out when a rolling tire grabs 'em, depending on where they're routed. Even with a steering stop the ones on the MINI are already chewed up.